If this goes ahead, it is likely to lead to pressure on the government to create a more federal UK, in which more responsibility could be handed over to Wales, Northern Ireland and the English regions.

Speaking on BBC Radio 4's Today programme, Allen said devolution has to be "a principle, not an expedient we allow when we've got a problem" that must apply throughout all the nations of the union.

"What's happened in Scotland is that the Scottish government now has the power to keep a certain amount of income tax in Scotland," he said. "I think that's good enough for Scotland, good luck to them, they deserve that and should have that. But it also should apply to England. England should also have income tax assignment, so that where you live, in London or Nottingham, can be clear about how much money is coming to our locality.

"Devolution isn't just for Scotland. This week I'd like to see Miliband, Clegg and Cameron issue a statement saying very clearly that we are in favour of both union and devolution, and perhaps to be credible, it can't apply only to Scotland, it must also find a way to apply to England, Wales and Northern Ireland."

In a blog for the Unlock Democracy campaign group, Allen went further, saying "bold, clear leadership is needed so that the failing Whitehall model, so successful in running an empire, can be left behind forever".

"The problem is that many of us just don't believe Whitehall on devolution, largely because it is evident that Whitehall does not yet really believe in it for England," he said. "Devolution is portrayed as an expedient, not a principle. This can be changed in an instant by casting off the shackles of our grotesque outdated over-centralisation, liberating the talents of all the nations of the union."